The Corona Dentis: Description of an Anatomic Variant with Technical Implications for Anterior Odontoid Screw Placement

World Neurosurgery
Fernando AlonsoR Shane Tubbs

Abstract

Type 2 odontoid fractures are the most common cervical fractures among the elderly. Neurologic deficit is usually caused by myelopathy as a result of posterior dens migration. Direct anterior screw placement provides stabilization and can preserve C1-C2 movement. The presence of a bony excrescence on the anterior superior tip of the dens may lead to placement of a screw of incorrect length. Twenty C2 dry specimens were examined for the presence of a corona dentis, which is a bony excrescence in the coronal plane near the apex of the dens. When identified, measurements of the corona dentis were performed using calipers and a ruler. In addition, anteroposterior (AP) and lateral fluoroscopy was performed on all specimens found to have a corona dentis. A corona dentis was found on 20% of our C2 specimens and had an average width of 9 mm and an average height of 4.5 mm. The average width of the dens did not vary as the normal tip of the dens transitioned into the coronae. In no specimen did the corona dentis seem to be composed of trabecular bone and it was seen as a superior projection of cortical bone on fluoroscopy. On fluoroscopy, the corona dentis could be identified on a true AP projection. In angulated AP views, fluoroscopic ...Continue Reading

References

Oct 15, 1993·Spine·M H Heggeness, B J Doherty
Nov 7, 1999·European Spine Journal : Official Publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society·E J MüllerG Muhr
Sep 30, 2000·Journal of Neurosurgery·R I ApfelbaumA Casey
Jul 25, 2006·Neurosurgical Focus·J S HarropG J Przybylski
Jan 2, 2010·Journal of Neurosurgery. Spine·Andrew T DaileyRonald I Apfelbaum
Aug 11, 2011·Clinical Orthopaedics and Related Research·Amar PatelAlexander R Vaccaro
Oct 4, 2011·Neurosurgical Focus·Marcus D MazurMeic H Schmidt
May 16, 2012·Clinical Orthopaedics and Related Research·Gang FengArndt P Schulz
Apr 16, 2016·The Indian Journal of Radiology & Imaging·Nishchint JainSurya N Bhaskar

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